These papers outline the known effects, positive and negative, on the natural environment. But public land policies and natural resource decisionmaking cannot be made on biological effects only. Social, political, and economic factors must also be considered.

Another great source of old documents and maps is Yosemite Online, put together by Dan Anderson. He also just completed scanning and posting all of Yosemite Nature Notes -- published between 1920 into the 80s. A great resource.